Block-signal system.



No. 845,220. PATBNTED FEB. 26, 1907.

F.B.GOREY. BLOCK SIGNAL SYSTEM.

APPLICATION FILED IEIBJB, 1904.

Withesses. Inventor. J/ Fred Bflor ey.

1, WW fltt'y.

'- UNITED STATES PATENT OFFICE.-

FRED B. COREY,"POF SCHENECTADY, NEW YORK, ASSIGN OR TO GENERAL ELECTRIC COMPANY, A CORPORATION OF NEW YORK.

BLOCK-SIGNAL SYSTEM.

Specification of Letters Patent.

Patented Feb. 26, 1907..

To all whom it may concern Be it known that I, FRED B. COREY, a citizen-of the United States, residing at Schenectady, county of Schenectady, State of N ew York, have invented certain new and useful Improvements in. Block-Signal Systems,- of

' which the followin is a specification:

My invention re ates to block-signal systems and its object is to provide a novel system particularly adapted for operation .by alternating current.

In block-signal systems in anism for the signals, as is well understood,

should be so arranged that when a train is'ina block the home signal at the entrance to that block and the distant signal at the entrance to the preceding block should be at danger. These two signals are ondiflerent semaphore-posts and the length of a block apart.

' the source for the track-circuits and signalment it is necessary that the circuit of' t e; operating mechanism forthe distant signal should extend the lengfh of the block. In another arrangement: t e necessity for these circuits, each one extending the length of a block, is done away with by the use of a polarized relay for controllin the circuit" of the operating mechanismof t e distant signal. By the use of the polarized relay the relays for the operating mechanismsfor all the signals, may be placed at the same points at which the signals themselves are placed. It

is evident that this latter'system possesses a number ofadvantages-over the former, both as regards cost'of installation and .maintenance. I

Whenalternating. current is em loyed as '1 the source for operating the-signa mechanisms, it is evident that a polarized cannot be used, such relays being suited to 'di- .rect current only: In certain casesalternatmg current has several advantages over direct current forusein such systems. I In which home and I distant signals are used the operating mech- When directcurrent is employed as through reversing-switches K and K;

act as return-conductor for the trolley-current the current in the rails interferes with the proper operation of the signal-relays when direct current is used in the track-circuit. When alternating current is used, it is pos sible to employ relays for the signals which are not affected-by direct current.

By my invention I provide a system in which alternating current may be used with its attendant advantages and in which all the advantages of the direct-current system without wires may be obtained.

My invent-ion will best be understood by reference to the accompanying drawing, in which A A A represent three blocks of a railway. r V

It will beseenithat only one of the rails is divided into blocks, the other rail being continuous throughout all the/blocks, so as to serve as return-conductor for trolley-current.

a represents a line-wire connected tea source of alternating current and conneqted to the continuous rail through the primaries of the transformers E E. With this ar rangement the continuous rail acts as re turn-conductor for the alternating current also; but a se aratereturn-conductor may be emp loyed',i preferred.

S ands represent two semaphore-posts at the entrance to blocks A and A, respectively. Each post carries a home signal H and a distant signal D, the signals for the block A being the home signal H on semaphore-post S and the distant signal D on semaphore-post S. Thus when a car is in block A, as indicated by C, signals H and D should beat danger, as shown, while signal Hisat safety position, since no car is in block A i The secondaries of transformers E and E are connected to the rail-circuligts .7 means of these switches the phase of the currents in the rail-circuits relative to the current. 1n line-wire a may be reversed: To the other ends of the blocks are connected the primaries of the transformers F and F.

These transformers serve a double purpose. By their use higher voltage may be obtained for operating the relays than could be imhpressed upon the rails, and in thesecond the case of an electric railway where the rails place they prevent the passage of. direct our: I

rent from the rails to the relays and conse-v quent interference'with theoperationof the ing-rods h h for the home signals H H, the

connection'between these rods and the sig-.

' nals being omitted for the sake of simplicity.

Rods h h also control the phase-c .anging switches K K for a purpose which will be hereinafter-explained.

, d (1 represent the operating-rods for the distant signals D. and D and arecontrolled by the coils j which are connected to batter ics B B ithrou -h switch-contactscontrolled by the relays J. 'The relays J J are reverseecurrent relays depending for their op- I eration upon the relative directions or phases of currents .in the stationary and movable windings. The stationary winding is con nected between line-wire a and the return- -rail, and the phase of the current in the stationary winding consequently depends upon the current in line-wire a. The movable coil is connected in shunt to the primary or secquently .flows in the ondary of transformers F F, and the phase or direction of current in the moving coils therefore .is'depen dent upon the phase of the currents in the rail-circuits.

' As has been already explained, the relative phase of the currents in the rail-circuits to the'currents in the line conductor a is control led by the phase-changing switches K K, the relative phase being I reversed when switch Kor K, as the case may be, is shifted fromone position to the other.

The operation is then as follows: With the car C in block A the rimary of transformer F is short circuited No current consesecondary of :transformer F, and relay I .is not energized. It allows its armature to fall, opening the circuit of coil t, which allows its armature to fall,"

permitting signal H to go to danger by gravity and shifting reversing-switch K to its lower position. I in the movable winding of relay J, and .consequently there is noturning effort in this re lay. The circuit of coil is accordingly open, anddistant signal D is allowed to go to danger under gravity. On the other hand,

since there is nocar in the blo'ck A transforn 'er F is energized, relay I holds up its ar-tna'ture, maintaining the circuit of C01l a closed and holding signal H at safety.

The movable wind'ng of relay J is also energized, but is so connected with reference to the stationary'wind-ing that when switch ,K, controlled by signal H, is in its lower position, as shown, the relative phases of the currents in the ntovable and stationary windings of relay J are such that the movable winding tends to turn in a counter-clockwise direction and remains against its stop, thereby-opening Further, there is no current the circuit'of coil and allowing distant signalD to goto anger by gravity. This condition of affairs continues as long as car 0 is iii-block A. When car 0 leaves block A,

transform er F is again energized, energizing relay I, whlch draws up its armature, closing the circuit of coil i. Coil 'i. consequently draws up its armature, restoring signal H to safety osition and at the san e time shifting the switch K to its upper position. By this *nzove'r ent of switch K the phase of current in block A relative to thecurrent in line wire a is reversed, and-the direction of torque of relay J is consequently reversed. The rrovahle coil of relay J tends to rotate in a clockwise direction, and thereby closes the circuit of coil 9', which draws up its armature and restores distant signal D to safety. Bignals H and D consequently properly indicate that blockA is clear. Distant signal D, however, still remains at danger, since I) the o eration of'the home signal one bloc ahea the current in the movable winding of.

relay J is in such a direction that the relay rei'nains against its stop, maintaining opencircuited the coil 7'. Distantsignal D is not restored to safety. until the car has passed out of the block ahead of block A and the home signal at the entrance-of that block has gone to safet reversing the direction of current throug i 3 1t will be understoodthat I have s owin the operating mechanisms for the signals .dia-

grammatically and, that any well-known forms of operating mechanisms may be used in the arrangement that I haveshown and described. Accordingly I do not desire .to limit myself to the particular construction the movable coil or 'rela 'J.

and arrangement of parts here shown, since changes which do not depart from the spirit of my invention and which are within the sec e ofthe appended claimswill be obvious to t ose skilled in the art.

' What I-claim as new, and desire to secure by Letters Patent of the UnitedStates, is-

1. In a block-signal system, a source ofalternatingcurrent connected to one end of" a block, two relays connected to the other end of. the block, one of'saidre'lays being respons'i've to a flow of alternating current and the other being res onsive to a reversal of current in the b ock relative to the source, means for reversing the current in the block relative-.- to the source, and signals controlled by said relays;

2. Inc block-signal system having home and distant signals, a source of alternating current connected to a block, means controlled by thehomesi'gnal of the following block forreversing the connections of said source to said block, a relay connected to the other end of said block and responsive to al ternating-current flow, a home signal controlled by said relay, a second relay connect' ed to said block and responsive :to a reversal tive to the source, and a distant signal conof current in said block relative to said source, and a distant signal controlled by said second relay.

3. In a block-signal system, a source of. alternating current connected to one end of each block, a relay connected to the other end of each block, a home signal controlled by each relay, means controlled by each home signal for reversing the relative connections of said source to the preceding block, a second relay connected to each block and responsive to a reversal of current in'the block rela-' trolled by each of said second relays.

4. In a block-signal system, a source of alternating current connected to a block,

, means for reversing the connections .of said source to the block, a relay having two rela-- tively movable windings, one of said windmgs being connected to said source and the other to said block, and a signal controlled by said relay.

5. In a block-signal system, a plurality of blocks, a source of alternating current connected to each block, a relay. responsive to" alternating-current flow connected to each block, a home signal controlled by each of said relays, a switch controlled by each home signal and arranged. to reverse the connections of said source to the preceding block, a relay for each block having two relatively movable windings, one of said windings be in connected to said source and the other to said block, and a distant signal controlled by each of the latter relays. 4

6. In a block-signal system having home and distant signals, a source of alternating current connected to a block,'aswitch controlled by the home signal of the following block arranged to reverse the connections of said source to said block, a relay connected through a transformer to the other end of said block and responsive to current-flow, a home signal controlled by said relay, a second relay connected to said block and responsive to a reversal of current in said block relative to said source, and a distant signal con trolled by said second relay.

7. In a block-signal system, a source of alternating current connected to the trackeircuit of a block, means for reversing the connections of said source to the track-circuit, a relay having two cooperating windings, one of said windings being connected to and'supplied with current from said trackcireuit, and the other-being supplied with alternating current of the same frequency nde endentlv of said track-circuit and a Si P circuit for controlling the signals, a plurality of block-sections, distant and home signals for each block, a relay controlled partly by b said track-circuit and partly by an external circuit, and means whereby one of the signal mechanisms of a distant block may ailect the track-circuit so as to reversely actuate .the said relay.

. 9] Ina railway block-signaling system having an alternating-current track-circuit for controlling the signals, a plurality of block-sections, home and distant signals for each block, a relay having two coils traversed respectively by two alternating currents having a predetermined phase relation to one another whereby an adjacent distant signal is caused to assume one position of indication, and means for so changing the said phase relation that the said distant signal is caused toassume another position of indication.

10. In a railway block-signaling system having a plurality of block-sections, each block comprising a track-circuit, home and distant signals for each block, a source of alternating-current supply for each trackcircuit, a relay adapte to respond in the movement of its armature to the presence or absence in its coils of current derived from the said source, and by such movement adapted to control the home signahanother relay for each block having one coil in circuit with the current source of the track-circuit and another coil supplied with alternating current derived from a source other than the track-circuit, and means for changing the phase relation of the current in the two coils.

11. In a railway block-signaling system having a plurality of block-sections, each block comprisin a track-circuit, home and distant signals or each block, a source of alternating-current sup ly for each track-' circuit, a relay adapte to respond in the movement of its armature to the presence or absence in its coils of current derived from the said source, and by such movement adapted to controlthe home signal, another relay for each block havingone coil in circuit rela the said relay being adapted to respond in t e movement of its armature to the said changes in the. base relations of the two currents in'its' coi s, to control an adjacent distant signal.

In witness whereof I have hereunto set myhandthis 15th day of'Fe'bruary, 1904.

V FRED B COREY.

Witnesses BEnJA IN B. HULL, HELEN ORIIORD. 

